Hi there I have a 2002 1.8 tdci focus and I live in Tenerife, when I go up to drive at altitude approx 7000ft above sea level the car drives fine. I turn off the engine and it starts again perfectly but the turbo stops working. When I get back down to about 3000ft I switch off the engine and restart and the Turbo works again and I have full power as normal. Something to do with thinner air I suppose but other cars with turbo's seem to be fine. Can someone advise please. There are no warning lights that come on?